In the early development of cargo-container handling systems, one initial and basic requirement was the guiding of spreaders into coupling relation with cargo containers. Vigorous efforts to provide guide devices have caused a number of designs, some proprietary, to emerge. Among the most successful is the type of guide located at the corners of a spreader comprising a linearly L-shaped member forming a lower transversely dihedral portion with a flaring skirt adapting it to fit around a vertically extending corner of a container. This type of guide may be fitted with a lower planate section and mounted between corners over a spreader frame side or end rail. Such a guide is ordinarily operated by a circular hydraulic motor in coaxial relation with a swing axis of the guide located in laterally inward relation with the periphery of the frame. There are other types of guides in use which engage the vertical sides rather than the corners of a container. Many of the guide mechanisms are not adaptable for manual operation. An object of the present invention is to provide an alternate mechanism for operating guides of L-shaped configuration which may be located inwardly of the vertical as well as the horizontal periphery of the spreader frame. It is further desirable that an actuating mechanism be provided which is adapted for operating guides at any point along the horizontal periphery of the frame. Another object is to provide mechanism of simple inexpensive design adaptable for either manual or power operation. Manual operation is important in low cost spreaders which are provided for occasional use and are constructed without electrical or hydraulic servomechanisms.